Transfer the paneer cubes to a large bowl or plate, and add salt and oil, gently mix well to coat the paneer cubes.
Add the garlic powder, lemon juice and also onion powder and black pepper powder (if using) also to the paneer cubes, gently mix the cubes to combine all ingredients so the paneer cubes will be coated nicely with the spices. Make sure you mix gently to avoid the paneer cubes crumbling.
Let it sit for about 15 minutes for marination (this step is optional, you may also directly bake this if you want to do it quickly. However, marinating the paneer will help the paneer slices to absorb the flavors more).
Line a baking sheet with non stick silicon mat or non slip baking mat (which will make the work easy as the paneer tends to stick to the pan while baking). (You may also use good quality aluminium foil, however the paneer tends to slightly stick to the aluminium foil which you will need to gently release once the baked paneer is cooled.)Lay the paneer cubes in a single layer (you can discard any excess oil or water residue from the bowl, and just transfer the paneer cubes to the baking sheet).
Bake for about 10 to 12 minutes, as the paneer will get nicely cooked by this time, leaving a tender and soft texture inside and a nice crispy outside.Allow the paneer slices to completely cool down if sticking to the foil (if using foil) so you can gently release the paneer slices without breaking them. If you try to release the paneer while it's still hot, it will be difficult and the paneer may break. So make sure to let them cool down completely (this will take only few minutes) so you can easily take them off.